1. Field of the Invention
The present invention relates to a method and an apparatus for measuring the temperature of a semiconductor element, the surface of which is formed with not less than two materials having different emissivities, based on the amount of infrared emission.
2. Related Background Art
As disclosed by G. A. Benett et al. in "IEEE TRANSACTIONS ON COMPONENTS, HYBRIDS AND MANUFACTURING TECHNOLOGY (pp. 690-695, VOL.12, NO.4, DECEMBER, 1989)," in the conventional method for measuring temperature based on infrared light, the emissivity of one kind of material having a sufficient area formed on a semiconductor element is measured, and its temperature is determined from the amount of infrared emission emitted therefrom. However, many kinds of materials such as insulating films and metals are formed into patterns on the surface of a semiconductor element, and these patterns are in many cases micro-patterns. When the average temperature of a region having a sufficient area on the surface is to be determined, even if there is a fine temperature distribution, detection accuracy does not decrease to a large extent because the measured data can be averaged. But, when it is desired to fractionate each pattern and measure the temperature thereof, it is necessary to take a picture of the surface of the semiconductor element using an infrared camera having high special resolution and to process the data.
However, according to the above measuring method, the spacial resolution cannot be improved without restrictions, because an optical lens has to be used for forming the image and infrared light having a long wavelength is used. The spacial resolution is in the order of 15 .mu.m according to the present technology, which is insufficient for measuring the temperature of a highly integrated semiconductor element.